When the going gets tough, rugged connectors deliver
Robust components are needed to make the grade from operating room to oil rig
When you’re designing equipment for extreme conditions or critical situations, high performing components are essential, and rugged connectors offer a reliable solution for the toughest situations. Rugged connectors are engineered for a variety of demanding applications, including extreme temperatures, humid or wet conditions, or in situations when compromised equipment or failure is not an option, such as military operations, medical equipment, broadcasting, testing, or data transmission. Most rugged connectors are made of brass or aluminum and are sealed to protect against dirt and water and/or gasses. Many use copper conductors, and some integrate gold to further enhance conductivity.
What to consider: application environment and risk
Whether you’re designing equipment for use in automobiles cruising highways in the US, oil rigs in the Gulf of Mexico, or instrumentation in Antarctica, it’s important to know how a rugged interconnect solution can impact the reliability of your solution. Design engineers suggest taking two important conditions into consideration when you are evaluating your solution: application environment and risk.
First, consider your application environment. If the equipment will be exposed to water, dirt, or other contaminants, extreme weather conditions, or will need to be cleaned or sterilized frequently, rugged connectors may be the right fit. For example, rugged connectors are ideal for broadcasting, when cameras or other equipment may be used outdoors in wet or cold conditions, or as a component of surgical instruments, when disposable or sterilizable options are required.
Second, rugged connectors are well suited to high risk applications, such as military or medical, when equipment reliability and accuracy is vital and leaves no margin for error. In test and measurement applications, rugged connectors protect the integrity of the data they collect, helping to insure accuracy, security, and prevent data loss.
Choosing the right rugged connector
The right connector solution — and that includes the cable — can help make your equipment or system design smaller, lighter, and easier to handle. It can also help improve functionality, reduce manufacturing costs, and increase durability and reliability. Consider these key factors to help you choose the right rugged connector for your equipment design.
1. Electrical needs. The voltage and current requirements of the application determine how much power each contact will need to carry; the size of the contact and the wire will determine the current carrying capacity of a contact. Higher density contacts allow more compact designs, without compromising performance. Check with the manufacturer to understand how current ratings and operating voltages are specified.
2. Additional functionality. Adding functionality to the rugged connector can help you design a device that’s easier to use and more cost effective. Hybrid connectors help reduce the number of connections required and result in having fewer cables to manage. A single connector may carry power plus signal, coax, fiber optics, liquid, and/or gas. The most common type of hybrid rugged connector features several larger pins for power and a high density group of smaller pins for signals.
3. Termination type. The type of termination impacts the assembly process and the ability to seal the connector. Connectors with solder contacts are usually easier to seal and protect against moisture ingress, while crimp contacts are easier to repair in the field. Consult with your manufacturing and design teams to make sure the right termination is selected for your application.
4. Environmental sealing. Rugged connectors are available with environmental sealing to protect against dust, water, and minerals or with hermetic sealing against gasses. When an environmental seal is required, an interface seals protects the junction between two connectors keeping unwanted particles away from connection. Mounting panel seals, seals for protecting contact areas, and cable sealing also provide protection for connectors and connections. Hermetically sealed connectors are traditionally sealed with glass, ceramic inserts, and epoxy.
The manufacturer’s IP (Ingres Protection) ratings indicate the level of protection against dust, dirt, and water at varying depth and operating time frames. A rating of IP68 or above indicates a true waterproof connection; however, be sure to consult with the manufacturer to understand the conditions that are represented. For example, an IP68 rating could mean 2 hours at 20 meters or 24 hours at 124 meters; be sure to choose the protection level that is appropriate for your application.
5. Materials. Rugged connector housing may be constructed of plastic, aluminum or brass; the material selected has an impact on reliability, weight, and cost. Brass connectors with nickel/chrome plating are wear resistant and have longer life cycles than other materials. Aluminum connectors are more lightweight, while plastics are ideal for limited reuse and disposable conditions. If you are considering plastic, adequate testing is advised to make sure it will withstand the wear-and-tear of the application. In medical equipment, make sure the connector can withstand any sterilization processes that may be required. Stainless steel is a high performance choice for corrosive environments or some food industry applications.
6. Reliability. Reliability is another factor to consider: how many times will the end user connect and disconnect the device? If a high number of mating cycles are predicted, look for a rugged connector suited to 5,000 to 10,000+ cycles. Dependability over time is essential is situations that may put lives at risk, such as in medical or military environments.
7. Miniaturization. As equipment and devices of all kinds are getting smaller and more lightweight, it’s possible to design a connector today that would have required two or three connectors only a few years ago. If you are considering a miniature connector, make sure that it can handle your voltage and current requirements. Small connectors are often difficult to terminate, so miniature plugs and receptacles are sold pre-wired to maximize reliability.
8. Raw cable and assemblies. When you choose the raw cable and cable assembly, consider the connector and the cable together to make sure they are compatible. As connectors get smaller, they may not be suitable for use with larger cables. A critical part of choosing cable for rugged applications is the cable jacket material. Polyurethane is an ideal candidate due to its high cut strength and its resistance to oils, coolants, and grease. Non-halogen and flame retardant grades are also available. If the cable is going to high stress or high flex environment consider using alloy conductors instead of copper they offer higher tensile strength (~33%) and high flex life with a moderate increase in dc resistance (~25%).
Once you’ve developed a specification checklist, make sure the manufacturer of the rugged connector you’re considering provides dependable service, reliable delivery and expert engineering support. Many standard connectors are available off the shelf, but customized or modified solutions can also developed to suit the unique needs of your application. Regardless of your specs, rugged connectors can help improve performance and functionality, while contributing to a design that’s lightweight, easy to handle, and reliable.